Apparatus for reading stadia.



E. J. YOUNG. APPARATUS FOR READING STLDIA.

APPLICATION FILED MAY 24, 1906.

922,833 Patented May 25, 1909.

WITNESSES.- Warn/7% WM 2 f: I By 9490M- I I W1 e 0 AzTm'Mm then point out the inveru ion in the socket g is the rod 1'.

EDGAR JOHN YOUNG,

Parana orinien OF BUENOS AYRES, ARGENTINA.

AEPARATUS FOR READING STADIA.

No. 922,883. Specification of A lication filed. May 24,

To all whom it may Be it known that citizen of the United.

tem of measuring distance with a telemeter 1 whereby the errors which are a part of the system now employed will be eliminated. l accomplish this result by the use of a new and improved apparatus for reading" stadia. i will first describe my invention as illustrated in the accompanying drawings, and

claim. In the drawings: Figure l is a general view of my improved apparatus. Fig. 2 is an illustrative view showing the operation with my improved apparatus.

(L represents an ordinary tripod provided with the plumb bob 7). c is a spindle which. is supported vertically on a horizontal plate, which plate is connect ed to the tripod by means of the. adjusting;

screws cl. Turning on the spindle c is the limb e.

fand g are sockets or guides. Passing into the sockctf is the rod 7t and passing into the These rods It and tare, as shown, graduated. T hose rods 71 and i are secured in their respective socket-sf and g by means of the clamp screws j. Supported upon the limb are the sight vanes l: in line with each other, which line is at right angles to the line through the center of the sockets or guides f and 9.

Z is a frame projecting vertically from the limb e.

m is a wire, one end connected to rod ft, the other end connected to rod i, said wirc passing over the top of frame Z.

a clamp screw adapted to clamp wire or to frame Z.

p is plain target movable upon rod 7t and adapted to be secured thereto at the desired position, by means of a clamp screw, not

shown.

g is a target provided with a Vernier r operated by a tangent screw, not shown. This target g is movable upon rod i and is secured thereto by means of a clamp screw, not shown.

8 is a fixed target carried by the upright I, EDGAR JonN YOUNG, a

Letters Patent.

1996. Serial N0. 318,595.

Patented. May as, ieoe.

! frame 1. This target is in a vertical line coin: I cident with the plumb bob. i In operating with this new stadia apparatus, instead of having the wires in the transit i horizontal, they are vertical. The appal ratus is leveled as an ordinary compass would l be. The limb e leveledoy means of the adjusting screws d and lGVQlf. The deflection of h and 9; from a horizontal line is corrected by means of wire m, which when these rods are brought into a horizontal condition is clamped by means of the clainp 0. The lrods l1 and '2. are then hxed 111 their sockets and clamped. division corresponding to about one half of l the estimated distance to be measured. 1 The telemeter a is then set u and the vanes l l: broughtmto ahnemont tierewith. The limb r is then clamped by clamp screw c.

As before stated, the stadia wires in in the telemctcr a, to read the distance with this apparatus, are placed vertically instead of horizontally. The telemeter being adjusted, the operation is as follows: Sght the. left hand stadia wire on the center of target p. in connection with a prearranged signal, the rod man will slide target q along rod i until nearly in line with the right hand stadia wire. This target is then clamped. 'T he. tangent screw is then operated to move the vernicr r to bring about an exact coincidence and thus read the intcrce )ted distance be tween targets p and (1. iv this arrangement, as may be seen, I employtwo targets with 'VOlIxltil, reading the 'ti-lolilOtliC distance armies to the line of collimation. The interval factor of the wires being known: distanco between points intercepted distai'ico on rod internal factor focal correction. The bearing is determined b observing s. This method of telemetrv implies the follow ing corollaries: 1st. By adjustment p and q are przu-ticalh equidistant and at right anelcs to the line. of vision, also their horizontal plane forms with the stadia wires an angle 90, hence the intercepted distance on p q is always proportional to the distance between the points of observation focal correction. 2d. The correction for reducing to the angle of incidence of the. vision with the ver tical plane of the rod, when observing from diil'erent levels, is hereby eliminated. 3d. It also elirniuatesthc error arising from refraction, owing to the greaterdensity of the 5 atmosphere traversed by the lower wire in- The target p clamped on a intercepted on the horizontal rod at rightill) the system now in practice. The vertical Wires intercept a horizontal distance, therefore in an atmosphere of homogeneous density. v

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

An improved apparatus for reading stadia comprising a central suptport, opposite rods 3 projecting horizontally om said su port, vanes on said su port in a line at rig t angles to the line 0 the rods at a point central of said apparatus, a target movable upon I each of said rods, 9. frame, a wire connected to said rods and passing over said frame, 15 f and a clamping device to secure said WlI: to said frame. I In testimony whereof I have affixed my signature in the presence of two witnesses. EDGAR JOHN YOUNG.

Witnesses:

5 J. REMSBURG,

LURIEL MORTTVELL. 

